<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Db
 * @subpackage Adapter
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: Ibm.php 24593 2012-01-05 20:35:02Z matthew $
 */
/**
 *
 * @see Zend_Db_Adapter_Pdo_Abstract
 */
require_once 'Zend/Db/Adapter/Pdo/Abstract.php';
/**
 *
 * @see Zend_Db_Abstract_Pdo_Ibm_Db2
 */
require_once 'Zend/Db/Adapter/Pdo/Ibm/Db2.php';
/**
 *
 * @see Zend_Db_Abstract_Pdo_Ibm_Ids
 */
require_once 'Zend/Db/Adapter/Pdo/Ibm/Ids.php';
/**
 *
 * @see Zend_Db_Statement_Pdo_Ibm
 */
require_once 'Zend/Db/Statement/Pdo/Ibm.php';

/**
 *
 * @category Zend
 * @package Zend_Db
 * @subpackage Adapter
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Db_Adapter_Pdo_Ibm extends Zend_Db_Adapter_Pdo_Abstract {

    /**
     * PDO type.
     * @var string
     */
    protected $_pdoType = 'ibm';

    /**
     * The IBM data server connected to
     * @var string
     */
    protected $_serverType = null;

    /**
     * Keys are UPPERCASE SQL datatypes or the constants
     * Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE, or Zend_Db::FLOAT_TYPE.
     * Values are:
     * 0 = 32-bit integer
     * 1 = 64-bit integer
     * 2 = float or decimal
     * @var array Associative array of datatypes to values 0, 1, or 2.
     */
    protected $_numericDataTypes = array(Zend_Db::INT_TYPE => Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE => Zend_Db::BIGINT_TYPE, Zend_Db::FLOAT_TYPE => Zend_Db::FLOAT_TYPE, 'INTEGER' => Zend_Db::INT_TYPE, 'SMALLINT' => Zend_Db::INT_TYPE, 'BIGINT' => Zend_Db::BIGINT_TYPE, 'DECIMAL' => Zend_Db::FLOAT_TYPE, 'DEC' => Zend_Db::FLOAT_TYPE, 'REAL' => Zend_Db::FLOAT_TYPE, 'NUMERIC' => Zend_Db::FLOAT_TYPE, 'DOUBLE PRECISION' => Zend_Db::FLOAT_TYPE, 'FLOAT' => Zend_Db::FLOAT_TYPE);

    /**
     * Creates a PDO object and connects to the database.
     * The IBM data server is set.
     * Current options are DB2 or IDS
     * @todo also differentiate between z/OS and i/5
     * @return void
     * @throws Zend_Db_Adapter_Exception
     */
    public function _connect () {
        if ($this -> _connection) {
            return;
        }
        parent::_connect ();
        $this -> getConnection () -> setAttribute (Zend_Db::ATTR_STRINGIFY_FETCHES, true);
        try {
            if ($this -> _serverType === null) {
                $server = substr ($this -> getConnection () -> getAttribute (PDO::ATTR_SERVER_INFO), 0, 3);
                switch ($server) {
                    case 'DB2' :
                        $this -> _serverType = new Zend_Db_Adapter_Pdo_Ibm_Db2 ($this);
                        // Add DB2-specific numeric types
                        $this -> _numericDataTypes['DECFLOAT'] = Zend_Db::FLOAT_TYPE;
                        $this -> _numericDataTypes['DOUBLE'] = Zend_Db::FLOAT_TYPE;
                        $this -> _numericDataTypes['NUM'] = Zend_Db::FLOAT_TYPE;
                        break;
                    case 'IDS' :
                        $this -> _serverType = new Zend_Db_Adapter_Pdo_Ibm_Ids ($this);
                        // Add IDS-specific numeric types
                        $this -> _numericDataTypes['SERIAL'] = Zend_Db::INT_TYPE;
                        $this -> _numericDataTypes['SERIAL8'] = Zend_Db::BIGINT_TYPE;
                        $this -> _numericDataTypes['INT8'] = Zend_Db::BIGINT_TYPE;
                        $this -> _numericDataTypes['SMALLFLOAT'] = Zend_Db::FLOAT_TYPE;
                        $this -> _numericDataTypes['MONEY'] = Zend_Db::FLOAT_TYPE;
                        break;
                }
            }
        } catch (PDOException $e) {
            /**
             *
             * @see Zend_Db_Adapter_Exception
             */
            require_once 'Zend/Db/Adapter/Exception.php';
            $error = strpos ($e -> getMessage (), 'driver does not support that attribute');
            if ($error) {
                throw new Zend_Db_Adapter_Exception ("PDO_IBM driver extension is downlevel.  Please use driver release version 1.2.1 or later", 0, $e);
            } else {
                throw new Zend_Db_Adapter_Exception ($e -> getMessage (), $e -> getCode (), $e);
            }
        }
    }

    /**
     * Creates a PDO DSN for the adapter from $this->_config settings.
     * @return string
     */
    protected function _dsn () {
        $this -> _checkRequiredOptions ($this -> _config);
        // check if using full connection string
        if (array_key_exists ('host', $this -> _config)) {
            $dsn = ';DATABASE=' . $this -> _config['dbname'] . ';HOSTNAME=' . $this -> _config['host'] . ';PORT=' . $this -> _config['port'] . ';PROTOCOL=' . 'TCPIP;';
        } else {
            // catalogued connection
            $dsn = $this -> _config['dbname'];
        }
        return $this -> _pdoType . ': ' . $dsn;
    }

    /**
     * Checks required options
     * @param array $config
     * @throws Zend_Db_Adapter_Exception
     * @return void
     */
    protected function _checkRequiredOptions (array $config) {
        parent::_checkRequiredOptions ($config);
        if (array_key_exists ('host', $this -> _config) &&  ! array_key_exists ('port', $config)) {
            /**
             *
             * @see Zend_Db_Adapter_Exception
             */
            require_once 'Zend/Db/Adapter/Exception.php';
            throw new Zend_Db_Adapter_Exception ("Configuration must have a key for 'port' when 'host' is specified");
        }
    }

    /**
     * Prepares an SQL statement.
     * @param string $sql The SQL statement with placeholders.
     * @param array $bind An array of data to bind to the placeholders.
     * @return PDOStatement
     */
    public function prepare ($sql) {
        $this -> _connect ();
        $stmtClass = $this -> _defaultStmtClass;
        $stmt = new $stmtClass ($this, $sql);
        $stmt -> setFetchMode ($this -> _fetchMode);
        return $stmt;
    }

    /**
     * Returns a list of the tables in the database.
     * @return array
     */
    public function listTables () {
        $this -> _connect ();
        return $this -> _serverType -> listTables ();
    }

    /**
     * Returns the column descriptions for a table.
     * The return value is an associative array keyed by the column name,
     * as returned by the RDBMS.
     * The value of each array element is an associative array
     * with the following keys:
     * SCHEMA_NAME => string; name of database or schema
     * TABLE_NAME => string;
     * COLUMN_NAME => string; column name
     * COLUMN_POSITION => number; ordinal position of column in table
     * DATA_TYPE => string; SQL datatype name of column
     * DEFAULT => string; default expression of column, null if none
     * NULLABLE => boolean; true if column can have nulls
     * LENGTH => number; length of CHAR/VARCHAR
     * SCALE => number; scale of NUMERIC/DECIMAL
     * PRECISION => number; precision of NUMERIC/DECIMAL
     * UNSIGNED => boolean; unsigned property of an integer type
     * PRIMARY => boolean; true if column is part of the primary key
     * PRIMARY_POSITION => integer; position of column in primary key
     * @todo Discover integer unsigned property.
     * @param string $tableName
     * @param string $schemaName OPTIONAL
     * @return array
     */
    public function describeTable ($tableName, $schemaName = null) {
        $this -> _connect ();
        return $this -> _serverType -> describeTable ($tableName, $schemaName);
    }

    /**
     * Inserts a table row with specified data.
     * Special handling for PDO_IBM
     * remove empty slots
     * @param mixed $table The table to insert data into.
     * @param array $bind Column-value pairs.
     * @return int The number of affected rows.
     */
    public function insert ($table, array $bind) {
        $this -> _connect ();
        $newbind = array();
        if (is_array ($bind)) {
            foreach ($bind as $name => $value) {
                if ($value !== null) {
                    $newbind[$name] = $value;
                }
            }
        }
        return parent::insert ($table, $newbind);
    }

    /**
     * Adds an adapter-specific LIMIT clause to the SELECT statement.
     * @param string $sql
     * @param integer $count
     * @param integer $offset OPTIONAL
     * @return string
     */
    public function limit ($sql, $count, $offset = 0) {
        $this -> _connect ();
        return $this -> _serverType -> limit ($sql, $count, $offset);
    }

    /**
     * Gets the last ID generated automatically by an IDENTITY/AUTOINCREMENT
     * column.
     * @param string $tableName OPTIONAL
     * @param string $primaryKey OPTIONAL
     * @return integer
     */
    public function lastInsertId ($tableName = null, $primaryKey = null) {
        $this -> _connect ();
        if ($tableName !== null) {
            $sequenceName = $tableName;
            if ($primaryKey) {
                $sequenceName .= "_$primaryKey";
            }
            $sequenceName .= '_seq';
            return $this -> lastSequenceId ($sequenceName);
        }
        $id = $this -> getConnection () -> lastInsertId ();
        return $id;
    }

    /**
     * Return the most recent value from the specified sequence in the database.
     * @param string $sequenceName
     * @return integer
     */
    public function lastSequenceId ($sequenceName) {
        $this -> _connect ();
        return $this -> _serverType -> lastSequenceId ($sequenceName);
    }

    /**
     * Generate a new value from the specified sequence in the database,
     * and return it.
     * @param string $sequenceName
     * @return integer
     */
    public function nextSequenceId ($sequenceName) {
        $this -> _connect ();
        return $this -> _serverType -> nextSequenceId ($sequenceName);
    }

    /**
     * Retrieve server version in PHP style
     * Pdo_Idm doesn't support getAttribute(PDO::ATTR_SERVER_VERSION)
     * @return string
     */
    public function getServerVersion () {
        try {
            $stmt = $this -> query ('SELECT service_level, fixpack_num FROM TABLE (sysproc.env_get_inst_info()) as INSTANCEINFO');
            $result = $stmt -> fetchAll (Zend_Db::FETCH_NUM);
            if (count ($result)) {
                $matches = null;
                if (preg_match ('/((?:[0-9]{1,2}\.){1,3}[0-9]{1,2})/', $result[0][0], $matches)) {
                    return $matches[1];
                } else {
                    return null;
                }
            }
            return null;
        } catch (PDOException $e) {
            return null;
        }
    }

}
